1. Field of the Invention
The present invention generally relates to an optical-pickup slider using an optical near-field and floating a predetermined distance above a high-density recording medium by an air flow, and a manufacturing method thereof.
The present invention further relates to a probe suitable for gathering incident light and emitting it to a sample to be measured or a recording medium for example, and a manufacturing method thereof, a probe array and a manufacturing method thereof, and, in more detail, to a probe which can gather incident light and generate an optical near-field and/or propagation light, a manufacturing method thereof, a probe array and a manufacturing method thereof.
2. Description of the Related Art
In a high-density information recording device using an optical near-field, as shown in Japanese Laid-Open Patent Application No. 9-198830 for example, recording and reading of information is performed on a recording-medium disc in a condition in which a slider of an optical pickup (optical-pickup slider) floats a distance equal to or smaller than hundreds of nanometers above a surface of the recording-medium disc by an air flow generated due to rotation of the recording-medium disc. As shown in FIG. 1, a slider 61 disclosed in Japanese Laid-Open Patent Application No. 9-198830 has a conical hole 62 passing between a side facing a recording medium and an opposite side formed therein, and has an aperture 63 on the side facing the recording medium. Light is incident from a larger opening of the hole 62 and an optical near-field is generated in the vicinity of the aperture 63.
As shown in FIG. 2, in a head of an information recording device using this slider 61, a light source 11 and a lens 12 are provided on the side opposite to the side of the slider 61 facing the recording medium 14. Light from the light source 11 is incident on the hole 62 of the slider 61 through the lens 12. By this light, an optical near-field generated in the vicinity of the aperture 63 is incident on the recording medium. Light incident on the recording medium has a diameter on the order of a diameter of the aperture 63, and it is possible to increase a resolution in recording/detecting, by this light, to one higher than 200 nm. Recording by this head is such that an energy applied to the recording medium 14 is changed, as a result of an intensity of light from the light source 11 being changed, and information is recorded on the recording medium 14. Further, detecting of information is performed using a photodetector 64 arranged on a side of the recording medium 14 opposite to a side facing the slider 61. Specifically, an optical near-field generated at the aperture 63 of the slider 61 generates propagation light as a result of contacting the recording medium 14, and the propagation light is detected by the photodetector 64, and, thus, information written on the recording medium can be detected. Thus, high-density recording can be performed using an optical near-field.
Further, M. B. Lee, T. Nakano, T. Yatsui, M. Kourogi, K. Tsutsui, N. Atoda, and M. Ohtsu, xe2x80x9cFabrication of Si planar aperture array for high speed near-field optical storage and readoutxe2x80x9d, Technical digest of the Pacific Rim Conference on Laser and Electro-Optics, Makuhari, Japan, No. WL2, pp. 91-92, July 1997 discloses, as shown in FIG. 3, a near-field optical probe 71 in which an inverse conical hole is formed in a silicon single-crystal substrate. When this probe 71 is made, a silicon single-crystal substrate 72 having thermal oxidation films 73 formed on both sides thereof, having a thickness of 270 xcexcm and having (100) plane orientation, as shown in FIG. 4A, photo resist 74 is coated on the thermal oxidation films 73, and an opening of 10 xcexcmxc3x9710 xcexcm is formed by photolithographic etching, as shown in FIG. 4B. Then, as shown in FIG. 4C, single-crystal anisotropic etching of silicon is performed by KOH solution of 80xc2x0 C. and a concentration of 10 weight %. Thereby, an inverse-pyramid-shaped hole 75 surrounded by a (111) plane of the silicon single-crystal substrate is formed. Then, as shown in FIG. 4D, photo resist 74 is coated on both sides, and a thermal-oxidation-film pattern having a large opening is made on the reverse side by photolithographic etching. Then, as shown in FIG. 4E, single-crystal anisotropic etching of silicon is performed from the reverse side by KOH solution again. At this time, the etching is stopped so that a through hole on the order of sub-microns is formed on the bottom of the pyramid-shaped hole 75. The etching is stopped so that the opening dimension equal to or smaller than sub-microns can be obtained as a result of an etching speed being previously measured and a time of etching stoppage being controlled. Then, as shown in FIG. 4F, fringes of the thermal oxidation films are removed by a dicing saw or by etching. Then, as shown in FIG. 4G, gold 76 is spattered, and, thereby, laser light is prevented from being incident on a recording material through portions other than the openings. Further, for assuring that the etching is stopped just in time, as shown in FIGS. 5A through 5G, an SOI (Silicon-On-Insulator) substrate 78 having an SiO2 film 77 in the middle is used. By this method, it is possible to obtain an opening having a diameter of 200 nm in a substrate.
An opening having a diameter equal to or smaller than 200 nm is formed on a side facing a recording medium in a slider disclosed in Japanese Laid-Open Patent Application No. 9-198830, and an evanescent wave is generated from this hole. However, this document does not disclose how to obtain this aperture, concretely. The slider has a thickness of millimeters in general, and it is not easy to form a very small aperture equal to or smaller than 200 nm through this thickness. Somewhat special technical measure is needed.
Further, the near-field optical probe shown in FIG. 3 is made, as a result of, as shown in FIGS. 4A through 4G, the inverse-pyramid-shaped hole being formed by anisotropic etching, and, then, the large opening being formed by etching from the reverse side. In this case, the opening dimension of the minute hole is determined by the depth of etching from the reverse side. In order to stop the etching just in time so as to obtain the opening dimension of tens of nanometers, the etching time of the reverse side is previously measured, and, thereby, the etching time is determined. However, thickness of silicon substrates varies on the order of tens of microns among the substrates. Further, an etching speed varies in a wide range depending on an amount of silicon dissolved in an etching liquid, an amount of oxide dissolved in the etching liquid, a slight temperature difference, and so forth. Accordingly, it is actually very difficult to stop etching just in time so as to achieve an opening dimension of tens of nanometers from a previously measured etching speed and a substrate thickness.
It is possible to obtain a desired small opening on the order of 50 nm with high repeatability by using an SOI substrate, and using an SiO film embedded in the middle as a film for stopping etching from a reverse side, as shown in FIGS. 5A through 5G. However, a thick fringe is produced around a surface on which the small opening is produced. Thereby, in this condition, it is not possible that the opening approaches a recording medium to a distance of tens of nanometers. Therefore, it is necessary to remove this fringe. However, because a thickness of a portion having the opening is on the order of 10 xcexcm, it is likely to be destroyed when or after the fringe is removed. In order to avoid such a situation, as shown in FIG. 6C or FIG. 7C, a thickness of a portion of a silicon substrate 72 in which an opening is provided is made small. Then, as shown in FIG. 6E or FIG. 7E, a pattern of silicon oxide for performing etching for providing the opening is formed on a bottom obtained by etching. Then, as shown in FIG. 6F or FIG. 7F, a hole 75 is formed by anisotropic etching. However, in this case, as shown in FIG. 6E or FIG. 7E, when photo resist 74 is coated, because a level difference of hundreds of microns exists from a surrounding fringe portion, it is not possible to coat the photo resist uniformly, and to form the pattern of silicon oxide with high accuracy.
A plurality-of-projection probe provided in a near-field optical microscope or a near-field optical recording optical head are made by a method in which an array of a plurality of recesses is transferred, in the related art, for example.
This near-field optical microscope or near-field optical recording optical head has a projection-type probe array arranged so that a distance between each projection and a sample is smaller than a wavelength of light used when the sample is measured. Thereby, the near-field optical microscope can measure physical properties of the sample by generating an optical near-field between each projection and the sample.
When the above-mentioned projection-type probe array is manufactured, first, a recess array having a plurality of recesses is made in an Si substrate as a result of anisotropic etching being performed on the Si substrate having a plane orientation of (100) plane for example. Then, the recesses are transferred onto another material such as metal material or dielectric material for example using the thus-made recess array. At this time, a surface of the recess array is covered by the material, such as metal or dielectric, other than Si. Then, the Si substrate is removed from the other material. Thereby, a projection-type probe array provided with a plurality of projections made of metal material or dielectric material is made.
The above-described projection-type probe array provided in the near-field optical microscope is used in a condition in which a distance between each projection and a sample is equal to or smaller than a wavelength of light. Therefore, it is important to control a height of each projection properly.
When a projection-type probe array is made as a result of a recess array being transferred onto a metal material or the like, a height of each projection is, as shown in FIG. 8, determined by a depth of a recess 1001 of the recess array 1000. The depth of each recess 1001 is determined by a width of the recess 1001 W=2H/tan54.74xc2x0≈1.414H because the recess 1001 is surrounded by an Si (111) plane. (The symbol xe2x80x98≈xe2x80x99 signifies xe2x80x98is approximately equal toxe2x80x99.)
However, the width of each recess 1001 involves an error on the order of approximately 10 nm due to variation in mechanical accuracy even when an electronic-beam exposing device is used. Accordingly, it is not possible to make uniform heights of respective projections of a projection-type probe array made by using the recess array 1000.
Further, when a single-projection probe is made, the above-mentioned problem involved in manufacturing of a projection-type probe array does not arise. However, the following problems arise.
First, a tip of a projection is not pointed, but, actually, is worked to a plane, and, thus, the projection is shaped as a truncated cone or pyramid. When a truncated-cone-or-pyramid projection is made in the related art, as shown in FIG. 9A, first, a truncated-cone-or-pyramid recess 3001 is made. Then, as a result of this being transferred, a projection is made. At this time, a planarity of a tip of the projection reflects a planarity of a bottom of the above-mentioned recess. When the recess having a bottom surface 3002 is made, a time of anisotropic etching is controlled and the etching is stopped before the entirety of the plane constituting the recess 3001 becomes a (111) plane (no bottom surface remains). In this case, a planarity of the bottom surface 3002 may deteriorate much due to a hillock or the like produced.
A planarity equal to or less than xcex/8 is needed for a tip of a projection-type probe, assuming that a wavelength of light to be emitted is xcex, for example. However, a planarity of the bottom surface 3002 of the recess 3001 made in the related art is far from reaching this. Accordingly, it is not possible to make a satisfactory projection-type probe by the related art.
Further, as shown in FIG. 9B, there is a case where an etch stop layer 3003 is previously made, and a bottom surface 3002 is obtained, when a recess 3001 is made, without controlling a time of etching. In this case, because it is possible to obtain a satisfactory planarity of the etch stop layer 3003, it is possible to make a projection-type probe satisfactory in a planarity view point.
However, in this case, a diameter of an opening D of a projection to be made is determined by an opening width W of the recess 3001 and a depth H of the recess 3001. The depth H has a sufficient accuracy in a local planarity view point as described above. However, variation within a sheet of wafer or between wafers may be very large as much as on the order of hundreds of nanometers.
Accordingly, when recesses 3001 are made to have uniform opening widths W, diameters of bottom surfaces 3002 (that is, diameters of openings at tips of projections) vary depending on variation in depths H.
In order to cope therewith, an opening width W may be made to change correspondingly to a variation of a depth H. However, it is not possible to measure a depth H precisely. Furthermore, it is not possible to change a dimension of a photo mask, actually.
Thus, even manufacturing of a single-projection probe which does not need consideration of making uniform heights of a plurality of projections involves problems on dimension accuracy in the related art.
An object of the present invention is to provide an optical-pickup slider and a manufacturing method thereof in which it is possible to make an aperture, which is not likely to be destroyed, by a single time of etching, with high accuracy and high repeatability.
Further, in an actual optical pickup-head slider 10, a ski 51 as shown in FIG. 10A or a pad 52 as shown in FIG. 10B is provided, for a purpose of smooth floating of the head without adhering a recording medium. Another object of the present invention is to make the ski 51 or pad 52 with high accuracy and high repeatability.
Furthermore, in an optical pickup-head slider, an aperture less than a wavelength of light used for generating an optical near-field and the optical near-field generated only from the aperture as a result of the light being incident on the periphery thereof are used for reading and writing of marks on a recording medium. However, because a thickness of a portion having the aperture is on the order of 10 xcexcm, light may be transmitted by a portion surrounding the aperture by a condition of a wavelength of the light. When the thus-transmitted light is incident on a recording medium, a dimension of each mark written there becomes larger and a recording density comes to be lowered, and S/N of a read signal comes to be lowered. Another object of the present invention is to solve these problems.
Another object of the present invention is to provide a probe and a manufacturing method thereof in which a dimensional accuracy is greatly improved.
Another object of the present invention is to provide a probe array having high efficiency and high resolution, and heights of respective projections are controlled to be uniform.
Another object of the present invention is to manufacture a probe array having high efficiency and high resolution, controlling heights of respective projections to make them uniform.
An optical-pickup slider according to the present invention is characterized in that a light-transmitting-property substrate is bonded to a surface of a layer having a tapered through hole, on which surface a larger opening of the tapered through hole exists. Thereby, it is possible to prevent the layer having an aperture from being destroyed.
It is preferable that the light-transmitting-property substrate has a thickness at least ten times a thickness of the layer. Thereby, it is possible to prevent the light-transmitting-property substrate and layer from being destroyed.
Further, it is preferable that glass or TiO2 is used as a material of the light-transmitting-property substrate when a wavelength of light to be incident is on the order of 2 xcexcm to the order of 0.4 xcexcm, but quarz glass, MgO, Al2O3, Y2O3 or diamond is used as a material of the light-transmitting-property substrate when a wavelength of light to be incident is equal to or shorter than 0.4 xcexcm. By thus changing the quality of material of the light-transmitting-property substrate in accordance with a wavelength of light to be input to the optical-pickup slider, it is possible to increase light transmittance.
An optical-pickup slider according to another aspect of the present invention is characterized in that a film of non-light-transmitting-property material is provided at least on an inclined surface of the abovementioned tapered through hole. Thereby, even when light is applied to the inclined surface of the hole providing an aperture, the light is blocked by the film of non-light-transmitting-property material, and, thereby, it is possible to generate only an optical near-field at the aperture on a recording-medium side. Thereby, it is possible to prevent a dimension of a writing mark from increasing so as to prevent a recording density from decreasing, and to prevent an S/N ratio of a read signal from decreasing.
It is preferable that the film of non-light-transmitting-property material is made of metal or resistivity-lowered semiconductor. Thereby, it is possible to block light positively.
Further, it may be that the non-light-transmitting film is made of eutectic of metal and the layer, or Si is used as a material of the layer and the film of non-light-transmitting-property material is formed as a result of resistivity of at least the inclined surface of the tapered through hole being lowered. Thereby, it is possible to easily form a light-blocking film and to block light positively.
An optical-pickup slider according to another aspect of the present invention comprises:
a first substrate;
a layer layered on the first substrate and having a thickness smaller than that of the first substrate, wherein:
a tapered through hole is made in the layer; and
after a light-transmitting-property substrate is bonded to a surface of the layer, the first substrate is removed so that an aperture at a tip of the tapered through hole is exposed.
In this arrangement, because the tapered through hole is made in the layer layered on the first substrate and having the thickness smaller than that of the first substrate, it is possible to make an aperture at a tip of the tapered through hole at high accuracy. Further, because the light-transmitting-property substrate is bonded to the surface of this layer and the layer having the aperture is supported by the light-transmitting-property substrate, the layer can be prevented from being destroyed. Furthermore, the first substrate is removed after the light-transmitting-property substrate is bonded to the surface of the layer, it is possible to stably expose the aperture with high dimensional accuracy at the tip of the tapered through hole of the layer.
An optical-pickup slider according to another aspect of the present invention comprises:
a first substrate;
a layer layered on the first substrate and having a thickness smaller than that of the first substrate, wherein:
a tapered through hole is made in the layer; and
after a light-transmitting-property substrate is bonded to a surface of the layer, the first substrate is removed, and, then, a ski shape or a pad shape is made at a position of an aperture at a tip of the tapered through hole in the layer.
Thereby, it is possible to make the ski shape or pad shape at high accuracy with high repeatability.
An optical-pickup slider according to another aspect of the present invention comprises:
a first substrate;
a layer layered on the first substrate and having a thickness smaller than that of the first substrate, wherein:
a ski shape or a pad shape having a tapered through hole is made in the layer; and
after a light-transmitting-property substrate is bonded to a surface of the layer,
the first substrate is removed so that an aperture at a tip of the tapered through hole is exposed.
Thereby, it is possible to make the high-accuracy ski shape or pad shape and the tapered through hole at the same time, and to simplify processes so as to reduce a cost.
An optical-pickup slider according to another aspect of the present invention comprises:
a first substrate;
a layer layered on the first substrate and having a thickness smaller than that of the first substrate, wherein:
a tapered through hole is made in the layer; and
after a film of a non-light-transmitting-property material is provided on at least an inclined surface of the tapered through hole, a light-transmitting-property substrate is bonded to a surface of the layer, and, after the first substrate is removed, a portion of the non-light-transmitting-property material is removed at an aperture at a tip of the tapered through hole so that the aperture is exposed.
By making the tapered through hole in the thin layer, and, after providing the film of the non-light-transmitting material at least on the inclined surface extending from the aperture of the tapered through hole, bonding the light-transmitting-property substrate to the surface of the layer, and removing the first substrate so as to expose the aperture at the tip of the tapered through hole, it is possible to easily form the film of non-light-transmitting-property material on the inclined surface of the tapered through hole having the aperture, and to improve a recording density and an S/N ratio of a read signal.
A method of manufacturing an optical-pickup slider according to the present invention comprises the steps of:
a) making a tapered through hole in a layer layered on a first substrate and having a thickness smaller than that of the first substrate; and
b) after bonding a light-transmitting-property substrate to a surface of the layer, removing the first substrate so as to expose an aperture at a tip of the tapered through hole.
In this arrangement, because the tapered through hole is made in the layer layered on the first substrate and having the thickness smaller than that of the first substrate, it is possible to make an aperture at a tip of the tapered through hole at high accuracy. Further, because the light-transmitting-property substrate is bonded to the surface of this layer and the layer having the aperture is supported by the light-transmitting-property substrate, the layer can be prevented from being destroyed. Furthermore, the first substrate is removed after the light-transmitting-property substrate is bonded to the surface of the layer, it is possible to stably expose the aperture with high dimensional accuracy at the tip of the tapered through hole of the layer.
A method of manufacturing an optical-pickup slider according to another aspect of the present invention comprises the steps of:
a) making a tapered through hole in a layer layered on a first substrate and having a thickness smaller than that of the first substrate; and
b) after bonding a light-transmitting-property substrate to a surface of the layer, removing the first substrate, and, then, making a ski shape or a pad shape at a position of an aperture at a tip of the tapered through hole.
Thereby, it is possible to make the ski shape or pad shape at high accuracy with high repeatability.
A method of manufacturing an optical-pickup slider according to another aspect of the present invention comprises the steps of:
a) making a ski shape or a pad shape having a tapered through hole in a layer layered on a first substrate and having a thickness smaller than that of the first substrate; and
b) after bonding a light-transmitting-property substrate to a surface of the layer, removing the first substrate so as to expose an aperture at a tip of the tapered through hole.
Thereby, it is possible to make the high-accuracy ski shape or pad shape and the tapered through hole at the same time, and to simplify processes so as to reduce a cost.
A method of manufacturing an optical-pickup slider according to another aspect of the present invention comprises the steps of:
a) making a tapered through hole in a layer layered on a first substrate and having a thickness smaller than that of the first substrate; and
b) after providing a film of a non-light-transmitting-property material on at least an inclined surface of the tapered through hole, bonding a light-transmitting-property substrate to a surface of the layer, and, after removing the first substrate, removing a portion of the non-light-transmitting-property material at an aperture at a tip of the tapered through hole so as to expose the aperture.
By making the tapered through hole in the thin layer, and, after providing the film of the non-light-transmitting material at least on the inclined surface extending from an aperture of the tapered through hole, bonding the light-transmitting-property substrate to the surface of the layer, and removing the first substrate so as to expose the aperture at the tip of the tapered through hole, it is possible to easily form the film of non-light-transmitting-property material on the inclined surface of the tapered through hole having the aperture, and to improve a recording density and an S/N ratio of a read signal.
A method of manufacturing an optical-pickup slider according to another aspect of the present invention comprises the steps of:
a) making a tapered through hole in a layer layered on a first substrate and having a thickness smaller than that of the first substrate; and
b) after forming eutectic of metal and the layer on at least an inclined surface of the tapered through hole, bonding a light-transmitting-property substrate to a surface of the layer, removing the first substrate so as to expose an aperture at a tip of the tapered through hole.
A method of manufacturing an optical-pickup slider according to another aspect of the present invention comprises the steps of:
a) making a tapered through hole in an Si layer layered on a first substrate and having a thickness smaller than that of the first substrate; and
b) after lowering resistivity of a surface of at least an inclined surface of the tapered through hole, bonding a light-transmitting-property substrate to a surface of the layer, removing the first substrate so as to expose an aperture at a tip of the tapered through hole.
Thereby, it is possible to easily form the film of non-light-transmitting-property material on the inclined surface of the tapered through hole having the aperture.
A probe according to the present invention comprises:
a substrate having a property of transmitting light; and
a projecting portion formed on the substrate, and made of a material having a refractive index higher than that of the substrate,
wherein the projecting portion has light from the substrate incident thereon, and generates one of or both an optical near-field and propagation light at a tip thereof.
In this arrangement, it is possible to greatly improve a dimension accuracy of the tip of the projecting portion.
A method of manufacturing a probe according to the present invention comprises the steps of:
a) bonding together a first substrate having a property of transmitting light and a second substrate comprising a high-refractive-index layer having a refractive index higher than that of the first substrate, an intermediate layer layered on the high-refractive-index layer and a supporting layer layered on the intermediate layer, in a condition in which the first substrate is in contact with the high-refractive-index layer;
b) removing the supporting layer included in the second substrate;
c) patterning by the intermediate layer exposed as a result of the supporting layer being removed;
d) etching the high-refractive-index layer using the patterned intermediate layer so as to form a cone-like or pyramid-like projecting portion on the first substrate; and
e) removing the patterned intermediate layer so that the probe having the cone-like or pyramid-like projecting portion made from the high-refractive-index layer on the first substrate be obtained.
In this arrangement, it is possible to greatly improve a dimension accuracy of a tip of the projecting portion.
A method of manufacturing a probe according to another aspect of the present invention comprises the steps of:
a) bonding together a first substrate having a property of transmitting light and a second substrate comprising a supporting layer, an intermediate layer formed on the supporting layer and a GaP layer formed on the intermediate layer, in a condition in which the first substrate and the GaP layer are in contact with one another;
b) removing the supporting layer included in the second substrate;
c) patterning by the intermediate layer exposed as a result of the supporting layer being removed;
d) etching the GaP layer using the patterned intermediate layer so as to form a cone-like or pyramid-like projecting portion on the first substrate; and
e) removing the patterned intermediate layer so that the probe having the cone-like or pyramid-like projecting portion made from the GaP layer on the first substrate be obtained.
In this arrangement, it is possible to greatly improve a dimension accuracy of a tip of the projecting portion.
A method of manufacturing a probe according to another aspect of the present invention comprises the steps of:
a) bonding together a first substrate having a property of transmitting light and a second substrate comprising a low-concentration layer having a refractive index higher than that of the first substrate and having a predetermined amount of impurities mixed therein and a high-concentration layer having impurities more than the predetermined amount of impurities mixed therein, in a condition in which the first substrate and the low-concentration layer are in contact with one another;
b) removing the high-concentration layer included in the second substrate;
c) forming a patterning material on a surface of the low-concentration layer exposed as a result of the high-concentration layer being removed and patterning by the patterning material;
d) etching the low-concentration layer exposed by the patterning so as to form a cone-like or pyramid-like projecting portion on the first substrate; and
e) removing the patterned patterning material so that the probe having the cone-like or pyramid-like projecting portion made from the low-concentration layer on the first substrate be obtained.
In this arrangement, it is possible to greatly improve a dimension accuracy of a tip of the projecting portion.
A method of manufacturing a probe according to another aspect of the present invention comprises the steps of:
a) bonding together a first substrate having a property of transmitting light and a second substrate comprising a n-type Si layer having a refractive index higher than that of the first substrate and a p-type Si layer, in a condition in which the first substrate and the n-type Si layer are in contact with one another;
b) removing the p-type Si layer included in the second substrate;
c) forming a patterning material on a surface of the n-type Si layer exposed as a result of the p-type Si layer being removed and patterning by the patterning material;
d) etching the n-type Si layer using the patterned patterning material so as to form a cone-like or pyramid-like projecting portion on the first substrate; and
e) removing the patterned patterning material so that the probe having the cone-like or pyramid-like projecting portion made from the n-type Si layer on the first substrate be obtained.
In this arrangement, it is possible to greatly improve a dimension accuracy of a tip of the projecting portion.
A method of manufacturing a probe according to another aspect of the present invention comprises the steps of:
a) bonding together a first substrate having a property of transmitting light and a second substrate comprising a high-concentration p-type Si layer having a refractive index higher than that of the first substrate and an n-type Si layer, in a condition in which the first substrate and the high-concentration p-type Si layer are in contact with one another;
b) removing the n-type Si layer included in the second substrate;
c) forming a patterning material on a surface of the high-concentration p-type Si layer exposed as a result of the n-type Si layer being removed and patterning by the patterning material;
d) etching the high-concentration p-type Si layer using the patterned patterning material so as to form a cone-like or pyramid-like projecting portion on the first substrate; and
e) removing the patterned patterning material so that the probe having the cone-like or pyramid-like projecting portion made from the high-concentration p-type Si layer on the first substrate be obtained.
In this arrangement, it is possible to greatly improve a dimension accuracy of a tip of the projecting portion.
A probe array according to the present invention comprises:
a substrate having a property of transmitting light; and
a plurality of projecting portions formed on the substrate, made of a material having a refractive index higher than that of the substrate, and like cones or pyramids having tips, positions of which are aligned,
wherein each of the plurality of projecting portions has light from the substrate incident thereon, and generates one of or both an optical near-field and propagation light at a tip thereof.
In this arrangement, it is possible to emit light at high efficiency with high resolution.
A method of manufacturing a probe array according to the present invention comprises the steps of:
a) bonding together a first substrate having a property of transmitting light and a second substrate comprising a high-refractive-index layer having a refractive index higher than that of the first substrate, an intermediate layer layered on the high-refractive-index layer and a supporting layer layered on the intermediate layer, in a condition in which the first substrate is in contact with the high-refractive-index layer;
b) removing the supporting layer included in the second substrate;
c) patterning by the intermediate layer exposed as a result of the supporting layer being removed;
d) etching the high-refractive-index layer using the patterned intermediate layer so as to form a plurality of cone-like or pyramid-like projecting portions on the first substrate; and
e) removing the patterned intermediate layer so that the probe array having the plurality of cone-like or pyramid-like projecting portions made from the high-refractive-index layer on the first substrate be obtained.
In this arrangement, it is possible to manufacture a probe array in which heights of respective projecting portions are controlled to be uniform by an intermediate layer.
A method of manufacturing a probe array according to another aspect of the present invention comprises the steps of:
a) bonding together a first substrate having a property of transmitting light and a second substrate comprising a supporting layer, an intermediate layer formed on the supporting layer and a GaP layer formed on the intermediate layer, in a condition in which the first substrate and the GaP layer are in contact with one another;
b) removing the supporting layer included in the second substrate;
c) patterning by the intermediate layer exposed as a result of the supporting layer being removed;
d) etching the GaP layer using the patterned intermediate layer so as to form a plurality of cone-like or pyramid-like projecting portions on the first substrate; and
e) removing the patterned intermediate layer so that the probe array having the plurality of cone-like or pyramid-like projecting portions made from the GaP layer on the first substrate be obtained.
In this arrangement, it is possible to manufacture a probe array in which heights of respective projecting portions are controlled to be uniform by an intermediate layer.
A method of manufacturing a probe array according to another aspect of the present invention comprises the steps of:
a) bonding together a first substrate having a property of transmitting light and a second substrate comprising a low-concentration layer having a refractive index higher than that of the first substrate and having a predetermined amount of impurities mixed therein and a high-concentration layer having impurities more than the predetermined amount of impurities mixed therein, in a condition in which the first substrate and the low-concentration layer are in contact with one another;
b) removing the high-concentration layer included in the second substrate;
c) forming a patterning material on a surface of the low-concentration layer exposed as a result of the high-concentration layer being removed and patterning by the patterning material;
d) etching the low-concentration layer using the patterned patterning material so as to form a plurality of cone-like or pyramid-like projecting portions on the first substrate; and
e) removing the patterned patterning material so that the probe array having the plurality of cone-like or pyramid-like projecting portions made from the low-concentration layer on the first substrate be obtained.
In this arrangement, it is possible to manufacture a probe array in which heights of respective projecting portions are controlled to be uniform by a patterning material.
A method of manufacturing a probe array according to another aspect of the present invention comprises the steps of:
a) bonding together a first substrate having a property of transmitting light and a second substrate comprising a n-type Si layer having a refractive index higher than that of the first substrate and a p-type Si layer, in a condition in which the first substrate and the n-type Si layer are in contact with one another;
b) removing the p-type Si layer included in the second substrate;
c) forming a patterning material on a surface of the n-type Si layer exposed as a result of the p-type Si layer being removed and patterning by the patterning material;
d) etching the n-type Si layer using the patterned patterning material so as to form a plurality of cone-like or pyramid-like projecting portions on the first substrate; and
e) removing the patterned patterning material so that the probe array having the plurality of cone-like or pyramid-like projecting portions made from the n-type Si layer on the first substrate be obtained.
In this arrangement, it is possible to manufacture a probe array in which heights of respective projecting portions are controlled to be uniform by a patterning material.
A method of manufacturing a probe array according to another aspect of the present invention comprises the steps of:
a) bonding together a first substrate having a property of transmitting light and a second substrate comprising a high-concentration p-type Si layer having a refractive index higher than that of the first substrate and an n-type Si layer, in a condition in which the first substrate and the high-concentration p-type Si layer are in contact with one another;
b) removing the n-type Si layer included in the second substrate;
c) forming a patterning material on a surface of the high-concentration p-type Si layer exposed as a result of the n-type Si layer being removed and patterning by the patterning material;
d) etching the high-concentration p-type Si layer using the patterned patterning material so as to form a plurality of cone-like or pyramid-like projecting portions on the first substrate; and
e) removing the patterned patterning material so that the probe array having the plurality of cone-like or pyramid-like projecting portions made from the high-concentration p-type Si layer on the first substrate be obtained.
In this arrangement, it is possible to manufacture a probe array in which heights of respective projecting portions are controlled to be uniform by a patterning material.
Other objects and further features of the present invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings.